Liquid crystal display

ABSTRACT

The present invention relates to a liquid crystal display including: a first substrate and an opposing second substrate; a liquid crystal layer interposed between the first substrate and the second substrate; a light blocking member disposed on the first substrate or the second substrate; a first field generating electrode disposed on the first substrate; a second field generating electrode disposed on the first substrate and including branch electrodes overlapping the first field generating electrode; and a gate line disposed on the first substrate and extending in a first direction. A branch electrode of the branch electrodes includes a central portion and a first edge portion disposed at one end of the central portion. A first angle formed between the first edge portion and a second direction is greater than a second angle formed between the second direction and the central portion, the second direction being perpendicular to the first direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2011-0016691, filed on Feb. 24, 2011, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Exemplary embodiments of the present invention relate to a liquidcrystal display.

2. Discussion of the Background

A liquid crystal display (LCD) is one of the most widely used type offlat panel displays (FPD). A liquid crystal display includes two displaypanels, on which field generating electrodes, such as a pixel electrodeand a common electrode, are formed. A liquid crystal layer is interposedbetween the two display panels. A voltage is applied to the fieldgenerating electrodes to generate an electric field in the liquidcrystal layer, and thereby control the orientation of liquid crystalmolecules of the liquid crystal layer. The orientation of the liquidcrystal molecules determines the polarization of incident light todisplay an image. The transmittance of the liquid crystal display may beincreased by properly controlling the liquid crystal molecules.

Each pixel electrode of the liquid crystal display is connected to aswitching element that is connected to signal lines, such as a gate lineand a data line. The switching element may be a thin film transistorthat transfers a data voltage to the pixel electrode through an outputterminal thereof.

In the liquid crystal display, the pixel electrode and the commonelectrode may be provided on a display panel where the switching elementis formed. One of the pixel electrode and the common electrode of theliquid crystal display may include a plurality of branch electrodes, andthe other may be rectangular. When the inclinations of the liquidcrystal molecules positioned at the edge of the branches are overlapped,textures may be generated. Also, if pressure is applied to the displaypane, the liquid crystal molecules may not recover, such that displaystains may be generated.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention reduce displaydeterioration, such as texture and stains, and simultaneously increasethe transmittance and aperture ratio of a liquid crystal display.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

Exemplary embodiments of the present invention provide a liquid crystaldisplay including two field generating electrodes, a pixel electrode anda common electrode, formed on a display panel. One of the fieldgenerating electrodes is rectangular, and the other includes a pluralityof branches overlapping the planar electrode.

A liquid crystal display according to an exemplary embodiment of thepresent invention includes: a first substrate and an opposing secondsubstrate; a liquid crystal layer interposed between the first substrateand the second substrate; a light blocking member formed on the firstsubstrate or the second substrate; a first field generating electrodeformed on the first substrate; a second field generating electrodeoverlapping the first field generating electrode and including aplurality of branch electrodes; and a gate line formed on the firstsubstrate and extending in a first direction. A branch electrode of thebranch electrodes includes a central portion and a first edge portiondisposed at one end of the central portion. The first edge portionextends lengthwise at a first angle with respect to a second directionthat is perpendicular to the first direction. The central portionextends lengthwise at a second angle with respect to the seconddirection. The first angle is larger than the second angle. The firstedge portion overlaps the light blocking member.

Exemplary embodiments of the present invention provide a liquid crystaldisplay including: a first substrate and an opposing second substrate; aliquid crystal layer interposed between the first substrate and thesecond substrate; a first field generating electrode disposed on thefirst substrate; a second field generating electrode overlapping thefirst field generating electrode and including branch electrodes; and agate line disposed on the first substrate and extending in a firstdirection. A slit between adjacent branch electrodes includes a firstedge, an opposing second edge, and a third edge that extends between thefirst and second edges. The first and second edges are generallyparallel, i.e., are equidistant from one another. An angle formedbetween the third edge and a second direction ranges from about 30degrees to about 75 degrees, the second direction being perpendicular tothe first direction.

According to an exemplary embodiment of the present invention, a fieldgeneration electrode of a liquid crystal display includes branchelectrodes, different portions of which extending at different angles. Alight blocking member is disposed over a curved end portion of thebranch electrodes, such that a transmittance decrease in the vicinity ofthe edge of the branch electrodes may be minimized.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a schematic layout view of two pixels of a liquid crystaldisplay, according to an exemplary embodiment of the present invention.

FIG. 2 is a top plan view of a field generating electrode of the liquidcrystal display shown in FIG. 1.

FIG. 3 is a cross-sectional view of the liquid crystal display shown inFIG. 1, taken along the line III-III′-III″.

FIG. 4 is an enlarged view of a portion A of the liquid crystal displayshown in FIG. 1.

FIG. 5 is an enlarged view of a portion B of the liquid crystal displayshown in FIG. 1.

FIG. 6 is a layout view of one pixel of a liquid crystal display,according to an exemplary embodiment of the present invention.

FIG. 7 is a view of a portion of an exposure mask used to form a fieldgenerating electrode of a liquid crystal display, according to anexemplary embodiment of the present invention.

FIG. 8 is a view of a portion of a field generating electrode of aliquid crystal display, according to an exemplary embodiment of thepresent invention.

FIG. 9, FIG. 10, FIG. 11, and FIG. 12 are views of a portion of anexposure mask used to form a field generating electrode of a liquidcrystal display, according to an exemplary embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. As those skilled in the art would realize,the described embodiments may be modified in various different ways, allwithout departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element or layer is referred to as being “on” or “connected to”another element or layer, it can be directly on or directly connected tothe other element or layer, or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon” or “directly connected to” another element or layer, there are nointervening elements or layers present.

FIG. 1 is a schematic layout view of two pixels of a liquid crystaldisplay, according to an exemplary embodiment of the present invention,FIG. 2 is a top plan view of a field generating electrode of the liquidcrystal display shown in FIG. 1, FIG. 3 is a cross-sectional view of theliquid crystal display shown in FIG. 1, taken along the lineIII-III′-III″, FIG. 4 is an enlarged view of a portion A of the liquidcrystal display shown in FIG. 1, and FIG. 5 is an enlarged view of aportion B of the liquid crystal display shown in FIG. 1.

Referring to FIGS. 1-5, the liquid crystal display includes a lowerpanel 100, an opposing upper panel 200, and a liquid crystal layer 3interposed between the display panels 100 and 200. The upper panel 200includes a light blocking member 220 and color filters 230, which areformed on an insulating substrate 210.

The light blocking member 220 includes a plurality of first lightblocking portions 221 mainly extending in a first direction Dir1, and aplurality of second light blocking portions 222 mainly extending in athe second direction Dir2. The second light blocking portions 222connect neighboring pairs of the first light blocking portions 221. Thefirst light blocking portion 221 and the second light blocking portion222 define an opening 225, through which light is transmitted. Eachsecond light blocking portion 222 is bent at least once between a pairof neighboring first light blocking portions 221.

The color filers 230 are disposed substantially within the openings 225of the light blocking member 220. The color filters 230 may be elongatedthroughout several pixel areas in the second direction Dir2. Each colorfilter 230 may display one primary color, such as red, green, or blue.

An overcoat 250 may be further formed on the light blocking member 220and the color filter 230. According to some embodiments, at least one ofthe light blocking member 220 and the color filter 230 may be disposedon the lower panel 100.

The liquid crystal layer 3 includes liquid crystal molecules 31. When noelectric field is applied to the liquid crystal molecules 31, the liquidcrystal molecules 31 may be aligned so that the long axes thereof areparallel to the surfaces of the two panels 100 and 200.

Alignment layers 11 and 21 are coated on the inner surfaces of twodisplay panels 100 and 200. The alignment layers 11 and 21 may behorizontal alignment layers. The alignment direction of the alignmentlayers 11 and 21 may be parallel to the second direction Dir2.Accordingly, the liquid crystal molecules 31 may be initially alignedparallel to the second direction Dir2.

The lower panel 100 includes a plurality of gate conductors formed on aninsulating substrate 110. The gate conductors include a plurality ofgate lines 121 and a plurality of common voltage lines 125.

The gate lines 121 transfer gate signals and extend substantially in thefirst direction Dir1. Each gate line 121 includes a plurality of gateelectrodes 124 that protrude in the second direction Dir2.

The common voltage lines 125 transfer a predetermined voltage, such as acommon voltage Vcom, extend substantially in the first direction Dir1,and may be substantially parallel to the gate lines 121. Each commonvoltage line 125 may include a plurality of expansions 126.

A gate insulating layer 140 is formed on the gate conductors 121 and125. The gate insulating layer 140 may be made of an inorganicinsulating material, such as silicon nitride (SiN_(x)) or silicon oxide(SiO_(x)).

Semiconductor stripes (not shown) are formed on the gate insulatinglayer 140. The semiconductor stripes extend substantially in the seconddirection Dir2. A plurality of semiconductor protrusions 154 extendtoward the gate electrodes 124 from the semiconductor stripes.

A plurality of ohmic contact stripes (not shown) and a plurality ofohmic contact islands 165 are formed on the semiconductor stripes. Theohmic contact stripes have a plurality of protrusions 163 extendingtoward the gate electrode 124 and forming an inverted “C” shape. Theprotrusions and the island ohmic contacts 165 face each other in pairswith respect to the gate electrodes 124 and overlap the semiconductorprotrusions 154. The ohmic contacts 163 and 165 may be made of amaterial such as n+hydrogenated amorphous silicon doped with n-typeimpurities, such as phosphorus, at a high concentration, or may beformed of a silicide.

Data conductors including a plurality of data lines 171 and a pluralityof drain electrodes 175 is formed on the ohmic contacts 163 and 165. Thedata lines 171 transfer data signals and extend substantially in thesecond direction Dir2, across the gate lines 121 and the common voltagelines 125. Each data line 171 includes a plurality of C-shaped sourceelectrodes 173 extending toward the gate electrode 124. The second lightblocking portion 222 extends along the data lines 171 and may cover themost of the data lines 171.

Each drain electrode 175 includes one bar-type end facing the sourceelectrode 173 across the gate electrode 124. Each drain electrode 175also includes another end having a wider area.

The gate electrode 124, the source electrode 173, and the drainelectrode 175 form a thin film transistor (TFT) along with thesemiconductor protrusion 154. The semiconductor stripes, except for thesemiconductor protrusions 154, may have substantially the same shape asthe data line 171, the drain electrode 175, and the underlying ohmiccontacts 163 and 165. The data line 171 and the underlying ohmic contactstripe and semiconductor stripe are bent at least once between a pair ofneighboring thin film transistors

A pixel electrode 191 is formed on the data conductors 171 and 175 andthe exposed semiconductor protrusion 154. A portion of the pixelelectrode 191 directly contacts the wide end of the drain electrode 175,and the remaining portion contacts the gate insulating layer 140. Thepixel electrode 191 receives a data voltage from the drain electrode175. The pixel electrode 191 may be made of a transparent conductivematerial, such as ITO or IZO.

The pixel electrode 191 is planar and fills up most of the region(hereafter referred to as “a pixel area”) enclosed by the gate line 121and the data line 171. The pixel electrode 191 may have sides that aresubstantially parallel to the gate line 121 and the data line 171, andupper or lower corners, at which the thin film transistor or theexpansion 126 is positioned, may be chamfered, but the shape thereof isnot limited thereto.

A passivation layer 180 is formed on the pixel electrode 191, the dataconductors 171 and 175, and the exposed semiconductor protrusion 154.The passivation layer 180 may be made of an inorganic insulator or anorganic insulator. The passivation layer 180 and the gate insulatinglayer 140 have a plurality of contact holes 181 exposing the commonvoltage line 125, e.g., part of the expansion 126. Contact holes 181 maybe positioned in at least every other pixel area.

Common electrodes 131, which may be made of a transparent conductivematerial such as ITO or IZO, are formed on the passivation layer 180.Referring to FIG. 1 and FIG. 2, one common electrode 131 is positionedin each pixel area, and the common electrodes 131 are connected to eachother.

Each common electrode 131 includes a pair of transverse outer stems 132,a pair of longitudinal outer stems 134 connected to the transverse outerstems 132, and branch electrodes 133. The branch electrodes 133 arepositioned between pairs of the longitudinal outer stems 134. The spacesbetween the branch electrodes 133 are may be referred to as slits.Common electrodes 131 adjacent in the second direction Dir2 share thetransverse outer stem 132 that is positioned therebetween, so that theneighboring common electrodes 131 are connected with the boundary of thetransverse outer stem 132. Common electrodes 131 adjacent in the firstdirection Dir1 share the longitudinal outer stem 134 that is positionedtherebetween, so that the neighboring common electrodes 131 areconnected with the boundary of the longitudinal outer stem 134.

The transverse outer stem 132 extends in the first direction Dir1 and issubstantially parallel to the gate line 121. The transverse outer stem132 includes expansions 137. The expansions 137 are positioned in atleast every other pixel area and receive a predetermined voltage, suchas a common voltage Vcom, from the common voltage line 125 and throughthe contact hole 181.

The longitudinal outer stem 134 and a plurality of branch electrodes 133therebetween are connected to a pair of transverse outer stems 132 andare parallel to each other. The longitudinal outer stem 134 and thebranch electrodes 133 are bent, such that central portions thereofprotrude in the first direction Dir1. The common electrode 131 isdivided into a first region Ra (first half) and a second region Rb(second half). In the present exemplary embodiment, the first region Rais positioned above the second region Rb. A vertex Pt2 is formed in eachof the branch electrodes 133, and the longitudinal outer stem 134 ispositioned at the boundary of the pixel area.

In the present exemplary embodiment, the boundary between the firstregion Ra and the second region Rb may correspond to an imaginarytransverse center line CT1 of the common electrode 131. In the firstregion Ra, the longitudinal outer stem 134 and the branch electrodes 133extend in the right upper direction from the imaginary transverse centerline CT1, while in the second region Rb, the longitudinal outer stem 134and the branch electrodes 133 extend in the right lower direction fromthe imaginary transverse center line CT1.

The branch electrodes 133 are bent at least once in the first region Raand the second region Rb. In each of the first region Ra and the secondregion Rb, the branch electrodes 133 may respectively include a pair ofedge portions ESA1 and ESA2 and a central portion MSA positionedtherebetween.

The edge portions ESA1 are directly adjacent to the imaginary transversecenter line CT1. Referring to FIG. 4, vertexes Pt3 of the branchelectrodes 133 and the longitudinal outer stem 134 are positioned at theboundary between the edge portions ESA1 and the central portions MSA.The edge portions ESA2 refer to portions of the branch electrodes 133positioned near the transverse outer stem 132. Referring to FIG. 5, thevertexes PO of the branch electrodes 133 and the longitudinal outerstems 134 are positioned at a boundary between the edge portions ESA2and the central portions MSA. The length of the edge portions ESA1 andESA2 is shorter than the length of the central portions MSA (lengthsextending in the second direction Dir2).

Referring to FIG. 1, FIG. 4, and FIG. 5, in edge portions ESA1 and ESA2,the angles A1 may be substantially the same. Hereafter, when an angle isdesignated, an acute angle will be designated rather than an obtuseangle.

In the edge portions ESA1 and ESA2, the angle A1 is larger than an angleA2 of the branch electrodes 133 in the central portion MSA. For example,in the edge portions ESA1 and ESA2, the angle A1 may range from 15degrees to 30 degrees. Also, the angle A2 may range from 0 degrees to 15degrees. Accordingly, referring to FIG. 4 and FIG. 5, the branchelectrodes 133 and the longitudinal outer stem 134 are bent at theboundary between the edge portions ESA1 and ESA2 and the central portionMSA. Particularly, the longitudinal outer stem 134 and the branchelectrodes 133 each have a vertex Pt3 at the boundary between the edgeportion ESA1 and the central portion MSA. The longitudinal outer stem134 and the branch electrodes 133 each have a vertex Pt1 at the boundarybetween the edge portion ESA2 and the central portion MSA.

The width of the branch electrodes 133 may be substantially uniform inthe central portion MSA or in most of the edge portions ESA1 and ESA2.In particular, the edges of the branch electrodes 133 may besubstantially parallel to (consistently spaced from) each other in thecentral portion MSA or in most of the edge portions ESA1 and ESA2.

Referring to FIG. 1 and FIG. 5, the edge portions ESA2 overlap the lightblocking member 220. For example, the edge portions ESA2 overlap thefirst light blocking portions 221 of the light blocking member 220. Inparticular, the vertexes PO of the branch electrodes 133 are positionedoutside of the opening 225 of the light blocking member 220. However,according to some embodiments, the vertexes Pt1 may be disposed insideof the opening 225, but within a distance D1 of a corresponding edge ofthe opening 225. The distance D1 may be from 0 to 3 μm. As describedabove, the edge portions ESA2 of the branch electrodes 133 arecompletely or partially overlapped with the light blocking member 220,such that a decrease of the transmittance may be minimized in the edgeportion ESA2.

The width W1 of the branch electrodes 133 may be in a range from about2.5 μm to about 3.5 μm, and the width W2 of the interval (slit) betweenthe branch electrodes 133 may be in a range from about 4.5 μm to about5.5 μm. That is, the pitch of the branch electrodes 133 may be in arange from about 7 μm to about 9 μm, about 7.5 μm to about 8.5 μm, ormay be about 8 μm, for example.

The width of the longitudinal outer stem 134 may be larger than thewidth of the branch electrodes 133. The longitudinal outer stem 134 maycover most of the data line 171.

In the present exemplary embodiment, the common electrode 131 issubstantially inversely symmetrical in shape, with respect to thetransverse center line CT1. However, the present invention is notlimited thereto. In the first region Ra and the second region Rb, theangles A1 and A2 may be different from each other.

Referring to FIG. 1, FIG. 2, FIG. 4, and FIG. 5, at least one of thedata line 171 and the second light blocking portion 222 extends parallelto the branch electrodes 133 and/or the longitudinal outer stem 134. Thebranch electrodes 133 and/or the longitudinal outer stem 134 aregenerally bent with the same angles in corresponding portions thereof.Likewise, the right and left edges of the pixel electrode 191 or theedge of the color filter 230 (not shown, however it is generallyparallel to the right and left edges of the pixel electrode 191) mayextend parallel to the branch electrodes 133 and/or the longitudinalouter stem 134, and may be bent with the same angles as the branchelectrodes 133 and/or the longitudinal outer stem 134. As describedabove, at least two of the data line 171, the second light blockingportion 222, the outer edge of the pixel electrode 191, or the outeredge of the color filter 230, and preferably all, are formed parallel tothe branch electrodes 133 and/or the longitudinal outer stem 134, suchthat the aperture ratio of the liquid crystal display is maximized,thereby improving the transmittance.

The pixel electrode 191 receives the data voltage through the thin filmtransistor, and the common electrode 131 receives the common voltageVcom, to generate an electric field in the liquid crystal layer 3. Assuch, the orientations of the liquid crystal molecules 31 of the liquidcrystal layer 3 are controlled to display an image.

As described in the exemplary embodiment of the present invention, byforming a plurality of regions having different angles at which thebranch electrodes 133 are inclined, it is possible to increase thereference viewing angle of the liquid crystal display and to maximizethe response speed of the liquid crystal molecules 31, by varying theinclination direction of the liquid crystal molecules 31 of the liquidcrystal layer 3. In the exemplary embodiment shown in FIG. 1 to FIG. 5,the common electrode 131 is divided into the first region Ra and thesecond region Rb, such that the liquid crystal molecules 31 are inclinedin two corresponding directions.

Also, without the boundary regions ESA1 and ESA2, the liquid crystalmolecules 31 in an outer boundary area of the common electrode 131, orat the boundary between the first region Ra and the second region Rb,may be apt align away from the alignment direction of the liquid crystalmolecules in the central portion MSA. Accordingly, such an alignment mayaffect the liquid crystal molecules in the central portion MSA andtextures may be generated. However, since edge portion ESA1 and ESA2 arebent, the orientations of the liquid crystal molecules 31 disposedadjacent thereto may be controlled, such that neighboring liquid crystalmolecules 31 are not counter twisted and/or colliding with each other.Also, the arrangement direction of the liquid crystal molecules 31reduces bruising that occurs when the display panels 100 and 200 arepressed inwards. The vertexes Pt1 are overlapped with the light blockingmember 220, manufacturing process margins are increased and thetransmittance decrease is minimized in the edge portions ESA2.

FIG. 6 is a layout view of one pixel of a liquid crystal display,according to an exemplary embodiment of the present invention. Theliquid crystal display is similar to the exemplary embodiment of FIG. 1to FIG. 5, so only differences therebetween will be described in detail.

Referring to FIG. 6, the light blocking member 220 and the color filter230 are formed on the insulation substrate 210. The light blockingmember 220 includes the first light blocking portion 221 and the secondlight blocking portion 222, which define the opening 225.

Gate lines 121 and common voltage lines 125 are formed on the insulationsubstrate 110, and a gate insulating layer 140, semiconductors,including protrusions 154, ohmic contacts, and data lines 171, and drainelectrodes 175 are sequentially formed thereon. The pixel electrode 191having a planar shape and contacting the drain electrode 175 is formedthereon. The pixel electrode 191 may be rectangular and may have sidesthat are substantially parallel to the gate line 121 and the data line171. The sides may be chamfered, but the shape thereof is not limitedthereto. A passivation layer 180 and common electrodes 131 aresequentially formed on the pixel electrode 191.

Each common electrode 131 includes a pair of outer stems 132 a andbranch electrodes 133 a extending therebetween. The outer stems 132 amainly extend in the second direction Dir2 and are parallel to the dataline 171. The branch electrodes 133 a connect the outer stems 132 a andform an oblique angle with respect to the first direction Dir1.

The branch electrodes 133 are each divided into a pair of edge portionsESA3 positioned near the outer stems 132 a and a central portion MSAdisposed therebetween. The width of the edge portions ESA3 is less thanthat of the central portion MSA (widths taken in the first directionDir1). Also, the angle A3 formed between the edge portion ESA3 and thefirst direction Dir1 in is larger than the angle A4 formed between thecentral portion MSA the first direction Dir1. In particular, the angleA3 may be between 15 degrees and 30 degrees, and the angle A4 may bebetween 0 degrees and 15 degrees. The angle A3 of each of the edgeportions ESA3 may be the same or may be different.

In the present exemplary embodiment, the boundaries between the edgeportions ESA3 and the central portion MSA, that is, the vertexes Pta ofthe branch electrodes 133 a, are positioned outside of the opening 225,so at to be overlapped with the light blocking layer 220. In thealternative, the vertexes Pta may be disposed in the opening 225, butwithin a second distance D2 from the corresponding edge of the opening225. The second distance D2 may be about 3 μm or less.

The common electrode 131 is shown to be positioned on the pixelelectrode 191, on the basis of the substrate 110. However, theorientations of the pixel electrode 191 and the common electrode 131 maybe reversed. In this case, the features of the common electrode 131described above may be applied to the pixel electrode 191, with thecommon electrode 131 receiving the common voltage and the pixelelectrode 191 receiving the data voltage to form an electric field inthe liquid crystal layer 3.

FIG. 7 shows an exposure mask used to form a field generating electrodeof a liquid crystal display, according to an exemplary embodiment of thepresent invention, and particularly, a portion of the exposure maskcorresponding to the portion A of the liquid crystal display shown inFIG. 1 and FIG. 4. Referring to FIGS. 1, 4, and 7, a transparentconductive material, such as ITO or IZO, is deposited on a passivationlayer 180, and a photosensitive film is coated thereon. Next, thephotosensitive film is exposed through the exposure mask, to form aphotosensitive film pattern. When the photoresist film has positivephotosensitivity, in which a part to which light is radiated is removed,the portions of the exposure mask corresponding to the common electrode131 may be opaque, and the remaining portions may be transparent.

Referring to FIG. 7, the exposure mask includes a first opaque portionMal and a second opaque portion Ma2. The first opaque portion Ma1corresponds to the branch electrodes 133, and the second opaque portionMa2 corresponds to the transverse outer stem 132.

The exposure mask includes first transparent portions Oa1 and secondtransparent portions Oa2. The first transparent portions Oa1 correspondsto the spaces (slits) between neighboring branch electrodes 133. Thesecond transparent portions Oa2 are generally rectangular, and havecorners that are connected to corners of the first transparent portionsOa1. The ends of the first transparent portions Oa1 are bent, so as tocorrespond to the ends of the branch electrodes 133. Each secondtransparent portion Oa2 has four edges that are substantiallyperpendicular, and the length L1 of one edge is at least about 2 μm,which is less than the resolution (e.g., 4 μm) of an exposure apparatus.The exposed transparent conductive material layer is etched, to form aplurality of common electrodes 131.

Since the second transparent portions Oa2 are formed adjacent to acutecorners of the first transparent portions Qa1 and are smaller than theresolution of the exposure device, the corresponding corners of thecommon electrode may be more sharply formed. In other words, the secondtransparent portions Qa2 compensate for the acute corners being smallerthan the resolution limit of the exposure device. Accordingly, theliquid crystal molecules can be more effectively controlled in thevicinity of the acute corners of the common electrode 131 and texturescan be reduced, thereby improving the display quality of the liquidcrystal display.

FIG. 8 is a view showing a portion of a common electrode of a liquidcrystal display, according to an exemplary embodiment of the presentinvention. Referring to FIG. 8, most of the liquid crystal displayaccording to an exemplary embodiment of the present invention is thesame as the liquid crystal display shown in FIG. 1 to FIG. 5, however,the shape of the end of the slit between the branch electrodes 133 ofthe common electrode 131 is different.

In the present exemplary embodiment, opposing both edges Eg2 of thecommon electrode 131 are parallel to each other, and an edge Eg1 at theend of the slit is obliquely inclined in the first direction Dir1. Theangle A5 between edges Eg2 and the second direction Dir2 may be betweenabout 0 degrees and about 15 degrees. Angle A6 between the edge Eg1 andthe second direction Dir2 may be between about 30 degrees and about 75degrees, while the angle formed between the edges Eg2 and Eg3 may be ina range from about 30 degrees to about 60 degrees.

Accordingly, display deterioration, such as the formation of texturesand the stains, may be reduced in the edge portion of the commonelectrode 131. Also, in the liquid crystal display according to thepresent exemplary embodiment, the branch electrodes 133 may include theedge portion ESA1 near the imaginary transverse center line CT1, likethe liquid crystal display shown in FIG. 1 to FIG. 5, or not. Severalcharacteristics and effects of the exemplary embodiment of FIG. 1 toFIG. 5 may also be applied to the present exemplary embodiment of FIG.8.

FIG. 9, FIG. 10, FIG. 11, and FIG. 12 are views of portions of exposuremasks used to form field generating electrodes of a liquid crystaldisplay, according to exemplary embodiments of the present invention.Referring to FIG. 9, an exposure mask according to the present exemplaryembodiment includes an opaque portion Ma3 corresponding to the branchelectrodes 133 of FIG. 8 and a transparent portion Oa3 corresponding tothe slit.

The exposure mask shown in FIG. 9 is similar to the mask shown in FIG.8. That is, an edge Ea3 at the end of the transparent portion Oa3 isobliquely inclined with respect to the first direction Dir1, and theangle formed by the edge Ea3 with the edge Ea2 is an acute angle. Theedge Ea2 may form the angle A5 with respect to the second directionDir2. The angle A5 may be greater than about 0 degrees and less than 15degrees. An angle A6 formed by the edge Ea3 with the second directionDir2 may be in a range from about 30 degrees to about 60 degrees. Asshown in FIG. 9, if the common electrode 131 is formed by using theexposure mask, the branch electrodes 133 shown in FIG. 8 may beobtained.

Referring to FIG. 10, an exposure mask according to the presentexemplary embodiment is similar to the exposure mask shown in FIG. 9.However a transparent portion Oa4 is additionally connected to thetransparent portion Oa3. The transparent portion Oa4 is generallytriangular, and in particular, may be in the form of a right isoscelestriangle. The length L2 of the two legs of the transparent portion Oa4may be between about 2 μm and the resolution of the light exposuredevice (e.g., 4 μm). For example, the length L2 may be about 3 μm.

Referring to FIG. 11, an exposure mask according to an exemplaryembodiment is similar to the exposure mask shown in FIG. 9. However, anadditional transparent portion Oa5 is connected to the transparentportion Oa3. The transparent portion Oa5 may be generally rectangular orsquare. The length L3 of edges of the transparent portion Oa5 maybetween 2 μm and the resolution (e.g., 4 μm) of the light exposuredevice. The length of edges connected to the transparent portion Oa3 maybe less than the length L3 and more than 1.5 μm.

Referring to FIG. 12, an exposure mask according to an exemplaryembodiment is similar to the exposure mask shown in FIG. 9. However, anadditional transparent portion Oa6 is connected to the transparentportion Oa3. The transparent portion Oa6 is generally trapezoidal. Thelength L5 of one of the two parallel edges of transparent portion Oa6may be more than 2 μm and less than the resolution of the light exposureapparatus (e.g., 4 μm), and the length L4 of the parallel edge may belonger than the length L5 and shorter than 9 μm.

As described above, if additional transparent portions Oa4, Oa5, and Oa6having various shapes like FIG. 10, FIG. 11, and FIG. 12 are added tothe transparent portion Oa3, the acute angle between the edge Egland theedge Eg2 may be sharp, such that the liquid crystal molecules may beeffectively controlled near the edge of the branch electrodes 133 andtexture may be further reduced.

The above exposure masks shown in FIG. 7, FIG. 9, FIG. 10, FIG. 11, andFIG. 12 are described for exposing the photosensitive film having apositive photosensitivity, however in a case of a photosensitive filmhaving negative photosensitivity, the transparency of the exposure maskshown in FIG. 7, FIG. 9, FIG. 10, FIG. 11, and FIG. 12 may be reversed.

Also, the disclosed exposure masks may be used to form the commonelectrode 131 including the branch electrodes 133. However, the presentdisclosure is not limited thereto. That is, the exposure masks may beused to form a pixel electrode

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A liquid crystal display comprising: a firstsubstrate and an opposing second substrate; a liquid crystal layerinterposed between the first substrate and the second substrate; a lightblocking member disposed on the first substrate or the second substrate;a gate line disposed on the first substrate and extending in a firstdirection; a first field generating electrode disposed on the firstsubstrate; and a second field generating electrode overlapping the firstfield generating electrode and comprising branch electrodes overlappingthe first field generating electrode, wherein, a branch electrode of thebranch electrodes comprises a central portion and a first edge portiondisposed at an end of the central portion, the first edge portionextends lengthwise at a first angle with respect to a second directionthat is perpendicular to the first direction, the central portionextends lengthwise at a second angle with respect to the seconddirection, the first angle is greater than the second angle, and thefirst edge portion overlaps the light blocking member.
 2. The liquidcrystal display of claim 1, further comprising a data line disposed onthe first substrate and crossing the gate line, wherein: the lightblocking member comprises a first light blocking portion covering thedata line; the branch electrode further comprises a second edge portionconnected to an opposing end of the central portion; the second edgeportion extends lengthwise at a third angle with respect to the seconddirection, the third angle is substantially the same as the first angle,and the first light blocking portion and the data line are parallel tothe branch electrodes.
 3. The liquid crystal display of claim 2, whereinopposing sides of the central portion are substantially parallel to eachother.
 4. The liquid crystal display of claim 3, wherein: the width ofthe branch electrodes ranges from about 2.5 μm to about 3.5 μm; and thedistance between adjacent branch electrodes ranges from about 4.5 μm toabout 5.5 μm.
 5. The liquid crystal display of claim 4, wherein thepitch of the branch electrodes ranges from about 7.5 μm to about 8.5 μm.6. The liquid crystal display of claim 2, wherein: the first edgeportion is bent from the central portion in a third direction; and thesecond edge portion is bent from the central portion in an opposingfourth direction.
 7. The liquid crystal display of claim 1, wherein: thewidth of the branch electrodes ranges from about 2.5 μm to about 3.5 μm,and the width of a slit between adjacent branch electrodes is in a rangeof about 4.5 μm to about 5.5 μm.
 8. The liquid crystal display of claim1, wherein the pitch of the branch electrodes ranges from about 7.5 μmto about 8.5 μm.
 9. A liquid crystal display comprising: a firstsubstrate and an opposing second substrate; a liquid crystal layerinterposed between the first substrate and the second substrate; a lightblocking member disposed on the first substrate or the second substrate;a first field generating electrode disposed on the first substrate; asecond field generating electrode overlapping the first field generatingelectrode and comprising branch electrodes; and a gate line disposed onthe first substrate and extending in a first direction, wherein, a slitbetween adjacent branch electrodes comprises a first edge, an opposingsecond edge, and a third edge extending between the first edge and thesecond edge, an angle formed between the third edge and a seconddirection that is perpendicular to the first direction ranges from about30 degrees to about 75 degrees, an angle formed between the third edgeand the second edge ranges from about 30 degrees to about 60 degrees,and an angle formed between the first edge or the second edge and thesecond direction is greater than 0 degrees and less than 15 degrees, andthe third edge overlaps the light blocking member.
 10. The liquidcrystal display of claim 9, further comprising a data line disposed onthe first substrate and crossing the gate line, wherein: the lightblocking member comprises a first light blocking portion covering thedata line; a branch electrode of the branch electrodes comprises acentral portion and an edge portion disposed at an end of the centralportion; the edge portion extends lengthwise at a first angle withrespect to the second direction; the central portion extends lengthwiseat a second angle with respect to the second direction; the first angleis greater than a second angle; and the first light blocking portion andthe data line are parallel to the branch electrodes.
 11. The liquidcrystal display of claim 10, wherein opposing sides of the centralportion are substantially parallel.
 12. A liquid crystal displaycomprising: a first substrate and an opposing second substrate; a liquidcrystal layer interposed between the first substrate and the secondsubstrate; a light blocking member disposed on the first substrate orthe second substrate; a first field generating electrode disposed on thefirst substrate; a second field generating electrode overlapping thefirst field generating electrode and comprising branch electrodes; and agate line disposed on the first substrate and extending in a firstdirection, wherein, a slit between adjacent branch electrodes comprisesa first edge, an opposing second edge, and a third edge extendingbetween the first edge and the second edge, an angle formed between thethird edge and a second direction that is perpendicular to the firstdirection ranges from about 30 degrees to about 75 degrees, and thethird edge overlaps the light blocking member.
 13. The liquid crystaldisplay of claim 12, further comprising a data line disposed on thefirst substrate and crossing the gate line, wherein, the light blockingmember comprises a first light blocking portion covering the data line;a branch electrode of the branch electrodes comprises a central portionand an edge portion disposed at an end of the central portion; the edgeportion extends lengthwise at a first angle with respect to the seconddirection, the central portion extends lengthwise at a second angle withrespect to the second direction, the second angle is smaller than thefirst angle, and the first light blocking portion and the data line areparallel to the branch electrodes.
 14. The liquid crystal display ofclaim 13, wherein opposing sides of the central portion are parallel.15. The liquid crystal display of claim 12, wherein an angle formedbetween the third edge and the second edge ranges from about 30 degreesto about 60 degrees.
 16. The liquid crystal display of claim 12, whereinan angle formed between the first edge or the second edge and the seconddirection is greater than 0 degrees and less than 15 degrees.
 17. Aliquid crystal display comprising: a first substrate and an opposingsecond substrate; a liquid crystal layer interposed between the firstsubstrate and the second substrate; a gate line disposed on the firstsubstrate and extending in a first direction; a first field generatingelectrode disposed on the first substrate; and a second field generatingelectrode overlapping the first field generating electrode andcomprising branch electrodes that extend in a second direction that isorthogonal to the first direction, each branch electrode comprising afirst half and an opposing second half, wherein, in each branchelectrode, the first half and the second half each comprise a first edgeportion, a second edge portion, and a central portion extending betweenthe first edge portion and the second edge portion, the first edgeportion of the first half being connected to the first edge portion ofthe second half, the first edge portions extend lengthwise at a firstangle with respect to a second direction that is perpendicular to thefirst direction, the second edge portions extend lengthwise at a secondangle respect to the second direction, the central portions extendlengthwise at a third angle respect to the second direction, the firstangle is greater than the second angle, and the second angle is greaterthan the third angle.
 18. The liquid crystal display of claim 17,further comprising a light blocking member disposed on the firstsubstrate or the second substrate, wherein the second edge portionsoverlap the light blocking member.